1. Field of the Invention
The present invention relates to a pressure sensor and a method for manufacturing the same.
2. Description of Related Art
A pressure sensor which is manufactured according to the MEMS (Micro Electro Mechanical Systems) technique is used as a pressure sensor and pressure switch to be provided in industrial machinery, etc.
Such a pressure sensor includes a diaphragm formed by processing, for example, a silicon wafer to be partially thin as a pressure receiving portion, and detects a stress and a displacement caused when the diaphragm is deformed by a pressure applied from the outside. Such a pressure sensor is provided with a hollow for generating a reference pressure and detects a pressure applied to the diaphragm as a relative pressure with respect to the reference pressure.
For example, there is a known pressure sensor provided with a hollow (reference pressure chamber) defined by a diaphragm and a glass substrate by anodically bonding a silicon substrate having the diaphragm formed by processing the silicon substrate to be partially thin by etching and the glass substrate (for example, Pyrex (registered trademark) glass).